Advanced computer technology enables electronic information to be readily processed by a portable information processing apparatus, such as a mobile computer. The portable information processing apparatus is used for a variety of purposes by an operator (user) who carries out industrial or commercial work. By way of example, in the case of an application for a distribution management system, the portable information processing apparatus is used in the work for collecting required items from a warehouse to display the items to be collected in the warehouse or register the collected items.
In the conventional portable information processing apparatus, the operator should significantly move the eyes to alternately watch electronic information displayed on the portable information processing apparatus and an object existing in the field. It is accordingly troublesome to visually check the relationship between the electronic information and the object. Further, the operator can not handle the object with hands while the portable information processing apparatus is manually operated; this results in poor workability.
An object of the present invention is thus to solve the above problems and to provide a technique that enables an operator to efficiently carry out another operation while observing a display of electronic information.